共查询到20条相似文献，搜索用时 62 毫秒
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为导出兼顾高精度与形式直观的高斯投影长度比与子午线收敛角公式,借助球面情况下的高斯投影正算、投影长度比、子午线收敛角公式都为闭合公式的优点,利用传统椭球面高斯投影公式对其进行适当改化。改化后以球面高斯投影闭合公式为主项,将改化项附加在主项后,得到改化后的高斯投影长度比和子午线收敛角公式,且改化项直观反映了球面高斯投影和椭球面高斯投影之间的差值关系,能一定程度上体现两者之间的内在联系。经算例验证,在高斯投影分带内,该改化公式兼具精度高、适应性好、表示形式简单的特点。 相似文献
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由于地球磁场的特殊位形,极区空间物理的观测研究在日地能量传输过程的研究中占有极其重要的地位。但由于我国地处中低纬地区,长期以来极区空间物理观测研究仍处于空白。南极中山站的建立为我国开展极区高空大气物理观测研究提供了条件。我国南极中山站(69°22’S,76°23’E,L=13.9)白天位于磁层极隙区,晚上处于极盖区,可以观测到丰富的日地能量传输过程的电离层征兆和极光现象,是开展极区高空大气物理观测研究的理想之地。充分利用我国南极中山站的优越地理位置,开展我国极区高空大气物理观测研究,为人类和平利用南极作出中国人应有的贡… 相似文献
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中国极地研究中心极地生物学研究室的主要任务是开展极地海洋生态学领域(主要是海冰区生态学)的有关主导过程、主要机制、重要环节、循环特性和动力学研究；极地生物资源(主要是极地微生物菌种和藻种资源)的调查研究、种质资源平台构建、资源利用技术研究与开发、资源战略软科学研究；极地低温生物(主要是极地低温微生物)的重要生物学基础理论研究、活性产物及其应用基础和生物工程技术研究；极地生态环境(主要是极地海洋生态环境)的监测研究和相应管理战略软科学研究；极地生物科学相关领域的科学装备技术整合和科学规划战略分析等领域研究。 相似文献
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The Polar Floats Program, an adaptation of midlatitude SOFAR float technology to the polar regions, is used to monitor subsurface circulation patterns over large spatial and temporal scales as well as to track mesoscale features in near realtime. The program is comprised of three major components that are now under development: an 80-Hz float transducer, American and French sea-ice-deployable listening stations using ARGOS data telemetry (ARS and SOFARGOS, respectively), and the software needed for real-time tracking. The adaptation of SOFAR technology to the planar regime demands modifications of the existing design from both environmental and acoustical standpoints. The authors describe the development and use of SOFAR technology within a relatively small sector of the north polar region that encompasses several thousand kilometers around Fram Strait (located between Greenland and Spitsbergen) 相似文献
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讨论了变形极坐标法的观测、计算和精度分析，给出了供应用的待定点点位中误差实用的计算式和点位误差等值线图。同时，对该法的应用提出了几点建议，供实际作业参考和应用。 相似文献
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A. V. Polyakov Yu. M. Timofeev Ya. A. Virolainen 《Izvestiya Atmospheric and Oceanic Physics》2008,44(4):448-458
The spectral aerosol-extinction coefficients (SAECs) obtained from SAGE III measurements are used to study the physical and integral microphysical characteristics of polar stratospheric clouds (PSCs). Different criteria for PSC identification from SAEC measurements are considered and analyzed based on model and field measurements. An intercomparison of them is performed, and the agreement and difference of the results obtained with the use of different criteria are shown. A new criterion is proposed for PSC identification, which is based on the estimate of how close the measured vector of the spectral attenuation coefficient is to a model distribution of the PSC ensemble. On the basis of different criteria, cases of PSCs are isolated from all SAGE III observations (over 30000). All selection criteria lead to a qualitatively and quantitatively similar space-time distribution of the regions of PSC localization. The PSCs observed in the region accessible to SAGE III measurements are localized in the latitudinal zones 65°–80° in the Northern Hemisphere and 45°–60° in the Southern Hemisphere during the winter-spring period. In the Northern Hemisphere, PSCs are observed within the longitudinal zone 120° W–100° E with the maximum frequency of PSC observation in the vicinity of the Greenwich meridian. In the Southern Hemisphere, the region of PSC observation is almost the same in longitude but with a certain shift in the maximum frequency of PSC observation to the west. This maximum is observed in the vicinity of 40°W, and the region of usual PSC observation is the neighborhood of 60° of the maximum’s longitude. The physical parameters of PSCs are estimated: the mean heights of the lower and upper boundaries of PSCs are 19.5 and 21.9 km, respectively, and the mean cloud temperature is 191.8 K. The integral microphysical parameters of PSCs are estimated: the total surface of NAT particles S NAT = 0.41 μm2/cm3; the total volume of NAT particles V NAT = 1.1 μm3/cm3; and, for all aerosol and cloud particles together, S is 2.9 ± 1.5 at a standard deviation of 2.7 μm2/cm3 and V is 2.8 ± 1.5 at a standard deviation of 4.2 μm3/cm3. A high frequency of PSC occurrence and high values of S and V in PSCs both for all particles and for NAT particles have been noted in January–February 2005 as compared to the rest of the period of SAGE III measurements for 2002–2005. 相似文献